I try not to write about eBay stuff too much cause it changes and disappears too quickly, but I came across these and they are cute and cozy-looking. There seem to be a bunch of size 5s (UK) and there seem to be some size 4s, though sadly I couldn’t find any higher sizes.
They look like a cross between Ugg boots and something you might actually want to wear.
If you’re quick, you can get some on eBay.